Accuracy of Optical Heart Rate Measurements for 10 Commercial Wearables in Different Climate Conditions and...

Area of Science:

• Wearable technology
• Biomedical engineering
• Sports science

Background:

• Continuous heart rate (HR) monitoring via commercial wearables is common.
• Independent testing of wearable HR accuracy in real-world conditions is limited, particularly during varied activities and stress.

Purpose of the Study:

• To evaluate the heart rate (HR) accuracy of 10 commercial wearable devices.
• To assess the impact of physical activity, cognitive stress, and climate on HR measurement accuracy.

Main Methods:

• Forty-five healthy adults underwent a protocol in controlled neutral, hot, and cold climates.
• Tested activities included rest, cognitive stress, steady walking, and intermittent walking.
• Compared 10 wearables (Fitbit, Garmin, Apple, Google, Polar, Xiaomi, Oura) against a gold standard ECG-derived HR using MAE, MAPE, CCC, and Bland-Altman analysis.

Main Results:

• Significant device-to-device variability in HR accuracy was observed.
• Fitbit Charge 6 and Google Pixel Watch 2 demonstrated high accuracy (MAE < 5 bpm, CCC > 0.87).
• Intermittent walking significantly increased HR measurement errors for several devices, while climate conditions had no significant impact.

Conclusions:

• Wearable HR accuracy is device-specific and influenced by activity type, not climate.
• Fitbit Charge 6 and Google Pixel Watch 2 are recommended for reliable health and sports monitoring.
• Context-aware interpretation and careful device selection are crucial for clinical and applied use.